Year current US$ 1970 3169645.18184447 1971 2568382.98531148 1972 389128.495974303 1973 368296.76088329 1974 699312.214821312 1975 509270.464246975 1976 848762.388945162 1977 971478.967429665 1978 907040.195020224 1979 747189.404049369 1980 625994.120939811 1981 831257.11088553 1982 691633.707285147 1983 0 1984 0 1985 0 1986 0 1987 0 1988 0 1989 0 1990 0 1991 0 1992 0 1993 0 1994 0 1995 0 1996 0 1997 0 1998 0 1999 0 2000 0 2001 0 2002 0 2003 0 2004 0 2005 0 2006 0 2007 0 2008 0 2009 0 2010 0 2011 0 2012 0 2013 0 2014 0 2015 0 2016 0 2017 0 2018 0 2019 0 2020 0 2021 0